US3893353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill and method of producing the same
Assignee: Gebrueder Heller GmbH
•
Filing: 1971-11-17
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Granted: 1975-07-08
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Expires: 1991-11-17
Abstract
Abstract The production of fluted drills from tubular cylindrical blanks preferably by cold-rolling so as to press at least one spiral chip flute into the blank by means of rotating pressure rollers and thereby displacing the material of the part of the blank into which the flute is impressed so as either to increase the length of the drill over the length of the original blank or to increase the diameter of the fluted part of the drill over the original diameter of the blank the untreated end portion of which remains cylindrical for clamping the drill in a tool holder. Although the rolling operation for producing the flutes also varies the shape of the bore in the blank, this bore will not be closed and its cross-sectional size will remain substantially the same as that of the bore in the blank and it may be used as a channel for passing a coolant to the cutting end of the drill which may consist of a suitably shaped plate of tempered steel or the like which may be hard-soldered to the end of the drill.
Inventors
- 👤 Hermann Lahmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:11
CPC Classifications
B; B21; B21H; B21H3/00; B21H3/10; B23; B23B; B23B51/00; B23B51/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
226 words
A method of producing a drill having a shank with a first longitudinal axis, a cutting end, a single channel coaxially extending along said first longitudinal axis, and at least one chip-removing flute extending from said cutting end in the outside surface and at least along a portion of the length of said shank, comprising the steps of supporting a tubular blank having a substantially cylindrical wall surrounding a bore of a substantially circular cross section which is coaxial with said blank, filling out said bore with a gaseous filling material, impressing said chip-removing flute into said blank by structurally deforming the material of said wall along at least a portion of the length of said blank by rolling said portion of said blank between two rollers, shifting one of said rollers in the direction toward the other of said rollers so that said portion of said blank is pressed to form said shank with said chip-removing flute thereby increasing at least one outer dimension of said portion by at least a part of the material being displaced by impressing said flute, thereby also deforming said bore in said portion so that said coaxial channel in said portion has elongated cross sections of substantially identical areas substantially coaxial with said first longitudinal axis, and cutting said deformed portion of said blank to form said cutting end.
Claim 2
Independent Claim
226 words
A method of producing a drill having a shank with a first longitudinal axis, a cutting end, a single channel coaxially extending along said first longitudinal axis, and at least one chip-removing flute extending from said cutting end in the outside surface and at least along a portion of the length of said shank, comprising the steps of supporting a tubular blank having a substantially cylindrical wall surrounding a bore of a substantially circular cross section which is coaxial with said blank, filling out said bore with a gaseous filling material, impressing said chip-removing flute into said blank by structurally deforming the material of said wall along at least a portion of the length of said blank by rolling said portion of said blank between two rollers, shifting one of said rollers in the direction toward the other of said rollers so that said portion of said blank is pressed to form said shank with said chip-removing flute thereby increasing at least one outer dimension of said portion by at least a part of the material being displaced by impressing said flute, thereby also deforming said bore in said portion so that said coaxial channel in said portion has elongated cross sections of substantially identical areas substantially coaxial with said first longitudinal axis, and cutting said deformed portion of said blank to form said cutting end.
Claim 3
Dependent Claim
45 words
A method as defined in claim 1, in which two of said flutes are impressed diametrically opposite to each other into said wall and said bore is thereby deformed so as to have substantially rectangular cross sections at spaced locations along said first longitudinal axis.
Claim 4
Dependent Claim
35 words
A method as defined in claim 2, in which the wall of said drill has its greatest thickness between said flutes and the edges of the cylindrical parts of the outer surface of the drill.
Claim 5
Dependent Claim
40 words
A method as defined in claim 1, in which by impressing said flute into said blank, the material into which said flute is impressed is displaced in the longitudinal direction of said blank so as to increase the length thereof.
Claim 6
Dependent Claim
49 words
A method as defined in claim 1, in which by impressing said flute into said blank, the material into which said flute is impressed is displaced so as to increase the outer diameter of the portions of said blank which are adjacent to both lateral sides of said flute.
Claim 7
Dependent Claim
43 words
A method of producing a drill as defined in claim 5, in which said flute is impressed only into a portion of the length of said blank and the fluted part thus formed has a larger outer diameter than the remaining unfluted part.
Claim 8
Dependent Claim
53 words
A method of producing a drill as defined in claim 1, further comprising the steps of filling out said bore in said blank with said filling material before deforming at least a portion of the length of said blank and removing said filling material from said bore after the deformation of said blank.
Claim 9
Dependent Claim
16 words
A method as defined in claim 7, wherein said filling material consists of an inert gas.
Claim 10
Dependent Claim
25 words
A method as defined in claim 1, in which at least a part of the length of said blank is deformed by cold-rolling the same.
Claim 11
Dependent Claim
89 words
A method according to claim 1, comprising the steps of cutting a slot in said cutting end so that said slot crosses said elongated cross section at the end of said axial channel in such a way that the ends of said elongated cross section extend at opposite sides thEreof beyond said slot, and securing a cutting plate in said slot so that said ends of said elongated cross section form a pair of opposite nozzles which exit from said axial channel at opposite sides of said cutting plate.
Claim 12
Dependent Claim
107 words
A method as defined in claim 2, in which said flutes are impressed into said blank so as to extend spirally about said first longitudinal axis of said shank, each of said rectangular cross sections having a second longitudinal axis which divides the rectangular cross-section into symmetrical halves, said second longitudinal axes of successive ones of said cross-sections of said channel forming a surface spirally twisting in one direction about said first longitudinal axis of said shank and each one of said second longitudinal axes of said elongated cross-sections of said channel extending substantially parallel to the bottom of a corresponding section of each of said flutes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |